1. Field of the Invention
The present invention generally relates to the technologies associated with a method for detection and output of surface images of thin-film devices, and particularly to a technique for the detection/output of surface images of, for example, dies (chips) built up on wafers at each process of the production line of semiconductor devices or the like.
2. Description of the Related Art
For example, particle inspection apparatus and visual inspection apparatus used for particle inspection and visual inspection in the manufacturing process of semiconductor devices detect and produce the coordinates and sizes (in some cases, types) of particles (foreign objects) and defects. In this case, the size of the region over which those particles and defects are detected at a time is about (tens of microns˜one-hundred and several-dozen microns, μm)×(tens of microns˜one-hundred and several-dozen microns, μm), but the image of the region over which the detection is made in the inspection is generally not stored.
In addition, even the conventional observing apparatus such as the so-called review station is able to change the size of the region over which those defects can be detected up to the maximum area of about several hundred μm×several hundred μm, but generally it does not store the detected images.
When defects are observed by using the above inspection apparatus or observation apparatus, the observer can know where the observed defect is on the corresponding die by giving the coordinates of the defect, die size and layout information of the die on a wafer. Moreover, if an observation function such as the review station is incorporated in the inspection apparatus or observation apparatus, a local neighboring image including the detected defect can be detected.
Even though similar particles are detected, they do not act similarly to cause defects or not to cause defects, or they act differently depending on what circuit pattern they belong to within a die. Therefore, since circuit patterns for various purposes are formed within each die, even a nonfatal defect sometimes might be misdecided as fatal under only local observation. Accordingly, it is useful to know where the corresponding defect is located within a die and what circuit pattern it belongs to. However, since the region over which the conventional inspection apparatus can observe is about several hundred μm×several hundred μm at most, it is difficult to intuitively know where the defect is located within a die and what circuit pattern it belongs to.
Moreover, when we consider the case when the film thickness QC (Quality Control) is performed after the film deposition and flattening process, for example, after CMP (Chemical Mechanical Polishing) as one of the flattening process, it is known that the film thickness after the process varies differently depending on the proportion of local circuit patterns within a die (hereinafter, referred to as pattern area rate). In this case, in order to effectively evaluate the film thickness, it can be considered to measure, for example, the maximum and minimum film thickness portions. However, under the local observation that the conventional thickness meter can make, it is difficult to know which part has the maximum or minimum film thickness.
In addition, various technical knowledge is required to determine the exact cause by defect analysis from the results of particle inspection and visual inspection. In that case, it is useful to directly observe defects. However, since the conventional apparatus generally does not store the images, the corresponding defect image must be again detected by any method when it is required.